Deadline dependent coding - a framework for wireless real-time communication

Abstract

A framework for real-time communication over a wire-less channel is proposed. The concept of deadline depend-ent coding (DDC), previously suggested by the authors, is further developed using soft decision decoding of block codes to maximize the probability of delivering informa-tion before a given deadline. The strategy of DDC is to combine different coding and decoding methods with automatic repeat request (ARQ) in order to fulfil the ap-plication requirements. These requirements are formulated as two Quality of Service (QoS) parameters: deadline (tDL) and probability of correct delivery before the deadline (Pd), leading to a probabilistic view of real-time communi-cation. An application can negotiate these QoS parame-ters with the DDC protocol, thus creating a flexible and dependable scheme. 1